I just got my Gamo Big Cat from Cabella's and I am enjoying it. Being a shot-gunner I am learning to site this thing. The scope (4X) has a lot of room to slide fore and aft. How do you position it for accuracy?

"I've been left for dead before but I'll still fight on, don't wait up, leave the light on, I'll be home soon"Chris Smither

You want to position the scope so you have a comfortable fit when you mount the gun, and have a full field of view in the scope. Being an air rifle, you shouldn't have to worry about recoil that might cause you to get a bloody eyebrow from the scope. Just make sure the crosshairs are level and you shouldn't have any problem. Start close when you sight in and then move out. With this gun I would think about 5-10 yards to start, then work out to where you think most of your shots will take place.

"Sticks and Stones may break my bones, but political correctness is killing me."

Mount the scope on the gun for the position you will shoot most (standing, Sitting etc.) bring it up with a good cheek weld and without adjusting your head front to rear, you are looking to see a nice clean picture thru the scope. You will need to move the scope fore or aft until all you see is a clear picture thru the scope. No haze around the edges. Most scopes are in the 2-3/4 to 3-3/4" eye relief range unless you have a scout or shotgun / bow type then the eye relief is longer. Make sure you have the crosshairs level and keep the mounts tight.

they are fin to knock over cans with and shooting eggs is fun too.

I never cared for a scope on a break barrel air rifle as it seems that by moving the barrel and locking it back up there would be no way to get the barrel in the same exact position 100% of the time. I am sure it works but I just use open sights on them as I am only shooting 15 to 20 yds anyway.